Writing data to Flash

Mon Dec 13 23:36:43 EST 2004

Hi Stephan,

Thank You very much for the information.

Here in our case we use a Redboot (bootloader) of Redhat. Please guide me 
where exactly can I find this driver generally in case of PPCBoot so that I 
can relate that to Redboot and find the same. Here in Redboot also we have a 
procedure to load data from RAm to flash but I am not clear how to copy data 
first to RAM.

To move data to RAM, can you please suggest how I can use this tftp command. 
Any procedure for the same would be of great help. Is there any 
documentation for the same(tftp).

Storing data in flash (in which case happens to be a string/key) is exactly 
what I require, Kindly suggest an approach.

Thanks,
Subrahmanyam.

----- Original Message ----- 
From: "Stephan Linke" <Stephan.Linke at epygi.de>
To: "Subrahmanyam" <subrahmanyam at navayuga.co.in>
Sent: Monday, December 13, 2004 09:06 PM
Subject: RE: Writing data to Flash

> Hi,
>
> we do access the flash by a a simple the flash driver provided with the 
> PPCBoot
> bootloader we use. This driver provides a couple of functions that can be 
> used
> in other C code too. The PPCBoot commandline also uses a simple copy 
> command to
> copy data from ram to any flash location. To move data to RAM (before 
> copy) a
> tftp command has to be used.
>
> I did work on storing data in flash. Now it is running (I hope).
>
> Regards, Stephan
>
>> -----Original Message-----
>> From: linux-mtd-bounces at lists.infradead.org
>> [mailto:linux-mtd-bounces at lists.infradead.org]On Behalf Of Subrahmanyam
>> Sent: Montag, 13. Dezember 2004 14:36
>> To: linux-mtd at lists.infradead.org
>> Subject: Re: Writing data to Flash
>>
>>
>> Hi Stephan,
>>
>> Your bootloader doesn't access flash using MTD !
>> In such case how do you access the contents of the flash!
>>
>> I'll start looking at physmap.c, If you don't mind can I ask you a 
>> question,
>> are you also working on storing data in the flash?
>>
>> I'll look into other possiblities also,
>>
>> Thanks,
>> Subrahmanyam.
>>
>>
>> ----- Original Message -----
>> From: "Stephan Linke" <Stephan.Linke at epygi.de>
>> To: "Subrahmanyam" <subrahmanyam at navayuga.co.in>;
>> <linux-mtd at lists.infradead.org>
>> Sent: Monday, December 13, 2004 06:23 PM
>> Subject: RE: Writing data to Flash
>>
>>
>> > Hi Subrahmanyam,
>> >
>> > I can't tell you anything about tools sources or environment of your
>> > bootloader.
>> > I don't even know if it actualy uses MTD to access the flash (our
>> > bootloader
>> > doesn't).
>> > So everything I can tell you is related to MTD drivers in linux
>> > environment. To
>> > have a first start in the mtd/maps directories I suggest locking at
>> > physmap.c
>> > which is a simple mapping that can be configured using the linux kernel
>> > configuration scripts ("make menuconfig" etc.).
>> >
>> > About the C progam: well this program is located in the /bin directory 
>> > of
>> > my
>> > linux root filesystem.
>> > About the /dev directory: this directory belongs to the linux root
>> > directory
>> > too. you can find out a lot about this directory by reading
>> > Documentation/devices.txt
>> > Most likely you can't use any of this in the bootloader. So you have to
>> > ask
>> > someone who knows you bootloader for more specific assistance.
>> >
>> > Regards, Stephan Linke
>> >
>> >> -----Original Message-----
>> >> From: linux-mtd-bounces at lists.infradead.org
>> >> [mailto:linux-mtd-bounces at lists.infradead.org]On Behalf Of 
>> >> Subrahmanyam
>> >> Sent: Montag, 13. Dezember 2004 13:24
>> >> To: linux-mtd at lists.infradead.org
>> >> Subject: Re: Writing data to Flash
>> >>
>> >>
>> >> Hi Stephan,
>> >>
>> >> Our target board consists of a IOP80321 processor with 16mb of flash 
>> >> and
>> >> 512mb ram which basically consists of RedHat ecos, but the basic build
>> >> environment in the host side is a Monta Vista Linux OS. When we 
>> >> connect
>> >> to
>> >> the target through "minicom" tool and when red boot is in the process 
>> >> of
>> >> booting, we basically stop the booting process by which red boot 
>> >> prompt
>> >> appears. It is here that fis-meaning flash image system comes into
>> >> effect,
>> >> wherein one can create partitions. It is in this context that I have
>> >> thought
>> >> of to load the key into the flash. Is this approach correct or not!
>> >>
>> >> You have said that you create a new flash mapping file in mtd/maps
>> >> directory, can you please suggest a method by which I can proceed. I 
>> >> have
>> >> looked into the mtd/maps directory in which there are number of files,
>> >> please suggest which file is the one I have to start with, for 
>> >> acheiving
>> >> writing data (key) to the flash, dynamically, after the target has 
>> >> been
>> >> identified by the host.
>> >>
>> >>
>> >> You have said you write a C program that uses normal file access
>> >> functions
>> >> to read/write the data, do you load this program/file into the flash 
>> >> or
>> >> does
>> >> it reside in the target. Where exactly does the flash partition inode 
>> >> has
>> >> to
>> >> be set up in the /dev directory. How to use this mknod tool.
>> >>
>> >> Kindly suggest an approach.
>> >>
>> >> Thanks,
>> >> Subrahmanyam.
>> >>
>> >>
>> >>
>> >>
>> >>
>> >> ----- Original Message -----
>> >> From: "Stephan Linke" <Stephan.Linke at epygi.de>
>> >> To: "Subrahmanyam" <subrahmanyam at navayuga.co.in>
>> >> Sent: Monday, December 13, 2004 05:25 PM
>> >> Subject: RE: Writing data to Flash
>> >>
>> >>
>> >> > Hi Subrahmanyam,
>> >> >
>> >> > what kind of operating system do you use? Unfortunately I don't know
>> >> > this
>> >> > "fis"
>> >> > tool.
>> >> > It sounds like you are not working in a linux kernel environment.
>> >> > The way I do it I am writing a "new" flash mapping file for mtd/maps
>> >> > that
>> >> > supports the flash layout for my target system. I do run the new 
>> >> > linux
>> >> > kernel
>> >> > which provides the new partition layout for the flash. And then I 
>> >> > write
>> >> > a
>> >> > new C
>> >> > program that uses normal file access functions to read/write the 
>> >> > data.
>> >> > The
>> >> > flash
>> >> > partition inode. has to be set up in the /dev directory using the 
>> >> > mknod
>> >> > tool. In
>> >> > the Documentation directory of the linux kernel you can find the
>> >> > correct
>> >> > device
>> >> > mappings for this.
>> >> > How to load the data into RAM depends verry much on you operating
>> >> > system.
>> >> > If you
>> >> > run linux you can simply use the ftp tool to place a copy of the 
>> >> > file
>> >> > in
>> >> > your
>> >> > filesystem. If you are runing some kind of bootloader you actualy 
>> >> > have
>> >> > to
>> >> > read
>> >> > the bootloader documentation. In that case I can be of verry little
>> >> > help.
>> >> > But
>> >> > most likely there is some tftp download support you can use.
>> >> >
>> >> > Regards, Stephan
>> >> >
>> >> >> -----Original Message-----
>> >> >> From: linux-mtd-bounces at lists.infradead.org
>> >> >> [mailto:linux-mtd-bounces at lists.infradead.org]On Behalf Of
>> >> >> Subrahmanyam
>> >> >> Sent: Montag, 13. Dezember 2004 11:25
>> >> >> To: linux-mtd at lists.infradead.org
>> >> >> Subject: Writing data to Flash
>> >> >>
>> >> >>
>> >> >> Hi Stephan,
>> >> >>
>> >> >> In my target there is a Redhat ecos wherein basically I can find 
>> >> >> out
>> >> >> the
>> >> >> usnused & used partiitions. To store data (ex: string) in the flash
>> >> >> firstly
>> >> >> I need to load the file into the RAM using the "fis load" command,
>> >> >> thereafter I need to create a partition in the flash based on the 
>> >> >> data
>> >> >> in
>> >> >> the RAM using the command "fis create".
>> >> >>
>> >> >> To acheive it, the first step is how exaclty should I load data 
>> >> >> into
>> >> >> the
>> >> >> (target's) RAM. After the data is available in the target's RAM 
>> >> >> then
>> >> >> only
>> >> >> I
>> >> >> can create a partition and store data into the flash.
>> >> >>
>> >> >> Kindly suggest a suitable approach.
>> >> >>
>> >> >> Thanks,
>> >> >> Subrahmanyam.
>> >> >>
>> >> >>
>> >> >> ______________________________________________________
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>> >> >> http://lists.infradead.org/mailman/listinfo/linux-mtd/
>> >> >>
>> >> >
>> >>
>> >>
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>> >
>>
>>
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